John e



UNITED STATES PATENT OFFICE JOHN R. PETERES, OF NEV YORK, N. Y.

IMPROVEMENT iN AIR-ENGINES.

Specification forming part of Letters Patent No. 36,964, dated November18, 1&672.

To all whom t may concern:

Be it known that I, JOHN R. PETERS, of

` the city, county, and State of New York, have invented a new anduseful Improvement in Air-Engines; and I do hereby declare that the 'iwith my improvement, the plane of section passing through theair-heating vessels. Fig. 2 is a plan of the same. Fig. 3 is a centralsection of one of the stuffing-boxes. Fig. 4 is a vertical sectionexhibiting the heaters with their plungers in a position different fromthose shown in Fig. l.

Similar letters of reference indicate corresponding parts in the severalgures.

rlhe first part of this invention relates to that class of air-engines(known as Stirlings) in which the airis heated in two vessels connectedwith opposite ends of the working-cylinder, by being transferred fromone end to the other of the said vessels alternately by means ofplungers working therein, the working-cylinder being double-acting.

In such engines, as heretofore constructed, the aforesaid plungers havebeen so connected that one always ascended while the other desoended,and vice versa, and the time occupied by the stroke of each has beengenerally i equal to that occupied by the stroke of the working-piston,and the consequence has been that the pressure of the air has been madeeffective upon the working-piston through but a portion of each stroke.

The object of this part of the invention is to render the said pressureeffective throughout the whole stroke of the working-piston; and to thisend it consists in so operating the two plungers that the one in eitherheating-1 vessel is stationary in its uppermost position with the spacebelow it full of heated air,

` while the working-piston is making the stroke v ter vessel to befilled with heated air to ,provduce the return-stroke oftheworking-piston,

by which means a more uniform and greater power is caused to bedeveloped in the opera` tion of the engine, and its working` is effectedwith greater economy.

To reduce as much as possible the size of the engine, I propose,generally, to use air mechanically compressed to a tension much greaterthan that of the atmosphere, and to do this economically I use the sameair over and over again. The power of engines in which the air is usedin this way depends upon the difference of temperature of the air at thetop and bottom-of the heatingvessel. The air when at the top of theheating-vessel is intended to be cooled either by circulating waterthrough pipes inside or by inclosing the upper part of the vessel withajacket,through which water is to be made to circulate.

The remaining part of my invention consists in an improvement in thepacking of the stuffing-boxes through which the rods of the plungers ofthe heating-vessel work, applicable also to other stuffing-boxes, forthe purpose of making the oil or other lubricating material employedtherein serve in a novel manner to aid in preventing leakage.

To enable others skilled in the art to make and use my invention, I willproceed to describe its construction and operation.

A is the working-cylinder, fitted with slide or other valves,like thoseused in a steam-engine,for the induction and eduction of t-he air, aseparate induction-valve being employed for each end of the cylinder,working ina separat valve-chest.

b b are the valve-chests. The valves are to be operated by an eccentric,tappets,vor other suitable means. A single valvechest and valve may,however, be used if check-valves opening toward such valve-chest beappliedin the pipes g g.

B B are the two heating-vessels, and P the furnace in which their lowerparts are received to heat the air below the plunger-s G C',

which are made of great depth and: filled with communicating with thesaid vessels below their plungers. The plungers C C are furnished withrods c c', working through 'stuffing-boxes in the covers of the vesselsB B, and the said rods are attached to separate levers D D, arranged towork on fixed fulcra d d in standards E E', which are secured on the topof the vesselsB B. Theselevers have applied to them springs F F', ofsufficient strength to raise the said levers and draw the plungers C Cup to the tops of the vessels B B.

G is a rock-shaft working in suitable bean ings in standards H H,arranged between the vessels B B. This shaft carries two toes, I I', foropera-ting on the two levers D D', and an arm, J, which is connected bya rod, L, with an additional crank, K, on the crank-shaftM of theengine,for the purpose of producingthe oscillation ofthe said rock-shaftby the revolution of the crank-shaft, the two toes andthe arm J being soarranged that when the working-piston in the cylinder A is at either endof its stroke the toes occupy the central position shownin Fig. 4, anddo not depress either of the levers D D', and consequently'leave boththe plungers C C at the tops of the vessels B B", but that during thestroke ofthe piston toward either end of the working-cylinder theplunger in the vessel B or B next to and in connection with that end ofthe cylinder is depressed by the action of its respective toe andallowed to rise again, the downward and upward stroke of the plungerbeing completed duringthe one stroke of the piston, and the otherplunger being in the meantime stationary in its highest position.

sition they respectively occupy when the working-piston is at the middleofthe stroke to the right, and in red outline in the positiontheyrespectively occupy when the said pistonis at the middle of its stroketo the left. By this mode of operating the plungers the trans- .fer ofthe hot air left in the hot lower part of each heatingvessel,after astroke of the working-piston has been produced by air from that vesselto the cold upper part thereof, and the transfer of cool air to thelower part of the vessel to be heated,are both completed during thetimethat the other vessel is supplying the cylinder, and the consequence 'isthat each vheating-vessel remains full of hot air during the -whole ofthat stroke of thel piston for which it supplies the air, and the effectof the eXpansion of the air is continued upon the vpiston throughout itswhole stroke, subject, ofcourse, to the gradual diminution of pressurein the heating-vessel consequentupon the expansion `as the strokeproceeds.

Instead of employing springs FF to raise madeso large that the .pressureof air under plungers in the same manner as the springs do after theyhavebeen forced down by the toes ofthe rock-shaft; or it may beunderstood vby engineers that a similar movement ofthe plungers may beeffect-ed by entirely different means.

Seisa compressing-pump having its piston connected with Atheworking-piston of the engine, to be thereby operated for the purpose ofcompressingair to be supplied through a pipe, N, with the branches ee tothe upper parts of the two vessels B B or through a pipe, N, to thereservoir or cooler R. This pump is only required to be set in operationon the starting of the engine to get up the desired pressure andoccasionally to make up for any escape by leakage, and at all othertimes the said pipe Nis shut off from the pump by a cock, h, and a cock,i, is opened to make the piston of the pump work .constantly inequilibrio. Ifthe cooling-vessel R, which constitutes the second part ofmy invention,were not used, the pipe N would have a direct connectionwith the upper parts of the heating-Vessels B B; but when the cooler isused,as represented in the drawings, to cool the exhausted air previously to its return to the upper parts of the heatingyessels B B, thesaid pipe is connected lbya pipe,'N, with the lower part of the saidcooler, and the upper part of the latter is connected with theexhaust-pipe Q.. rlhe coolingvessel R cools air by presenting a largesurface to the surrounding atmosphere; or it may be cooled by water. Theair entering it at the top and leaving it at the bottom causes thecoolest portionof its contents to be always supplied, as those portionssett-le toward the bottom by a natural law. In'Fig. l the plungers areshown in the po- To use this cooling-vesselsuccessfully, theworkingcylinder requires to be tted, like'the cylinder of asteam-engine,with induction and eduetion valves, and the pipes c crequire to lbe fitted with check-valves closing Lin an outward directionfrom the heatingvessels, which is contrary to the practice ofStirling,who used no Valves between the working-cylinderl and'the'heatingvessell "Without such valves `it would be objectionable tohave any more space Vthan is absolutely necessary between the cylin-.der and the heating-vessels, as a loss of power wouldbe consequent uponthe expansion of the airinto any such space.

vThe coolingfvessel represented is a simple ,cylinder cooled from thecontact of itseXterior by theatmosphere; but it may be constructed of aseries of `pipes running through'it, to lbe cooledalso by thecirculation of water or'of Athe atmosphere through such pipes; orinstead of such a vessel, a cooler may be made of a coil of kpipeexposed to the atmosphere. The object of this cooler may be likened lto.that ofthe condenser of a steam-engine, and

is vprecisely the reverse of what has been known as a regenerator, 7which has been ap- .plied to eur-engines.

lf it should be desired to take the air into the heaters at the pressureof the atmosphere and lto exhaust from the working-cylinder` into theatmosphere, the cooling vessel or cooler R is of course unnecessary, andin such case the pipes e e will be cut off near the heating-vessels,outside of the check-valves before mentioned. If desirable, the exhaustair may also be allowed to pass back from the Working-cylinder into theheating-vessels through the same pipes which supply theworking-cylinder. 'In this case, when the air passes back from theWorking-cylinder to the heating-vessels,the slide-valve of ihe cylinderwill operateas a check-valve, and will rise to allow the air to passback. A sufcient chamber or space, representing what may be termed anexhaust-passage, should be left under the slide-valve to atford room forthe compression of any exhaust air that remains at the end of theWorking-cylinder when the piston nears the end of its stroke. In casethe cooler is dispensed with the upper part of the cylinder may becooled by the application thereto of water, in accordance with the planof Stirling or others hereinbefore mentioned.

The cooler R can be used as a reservoir for compressed air,which can beheldin readiness to supply the engine when increased power istemporarily Wanted, in which case the engine may exhaust directly intothe atmosphere. This reservoir of compressed air would also be founduseful in compensating the engine for any loss 'of its air by leakage.

My improved stuffing-box is best illustrated in Fig. 3, which represents:it on a larger scale than the other igures. The gland T, which is usedto compress the packing 1c, as in any other stuffing-box, is made with adeep cut, Z, in its upper part for the reception of oil or otherlubricating material, and around the upper edge of this cup a leathercollar, fn, is secured by a clamping plate or ring, m, Which is held bythe same screw-bolts o o and nuts p p as are employed for securing thegland down upon the packing. The leather collar n is so constructed asto hug the plunger-rod c closely, and to be made to hug it the tighterby any pressure on its under side, like what is known as waterpacking-77Any air passing the packing 7c forces the oil or melted lubricatingmaterial against the collar n, and so causes it to hug the rod in such amanner as to prevent the air from esca-ping The lubricating materia-lthus applied, in combination with the leather collar, serves to preventthe said collar from being dried up by the heat and to keep the saidcollar soft and pliable.

I do not confine myself to the use of the within-described mechanicalmeans of producing the movement of the plungers, as various means may beemployed to produce the same movement; but

What T claim as my invention, and desire to secure by Letters Patent,is-

The construction of the stuling-box gland with an oil-cup, Z, andflexible collar n, combined substantially as herein described, for thepurpose set forth.

JOHN R. PETERS.

Witnesses:

R. GAWLEY, TIMOTHY SHINE.

